The global markets for disposal and/or repurposing of treated wood waste sources continues to increase and many landfills are not suited to accept the treated wood sources due to environmental concerns and/or the landfills are reaching their capacity for such waste sources. For example, in the U.S. alone approximately 20 million railroad ties are replaced annually and approximately 5 to 8 million of these railroad ties are landfilled or simply left onsite as environmental waste, representing approximately 500 tons of treated wood waste source available for processing. Similarly, about 4 million utility/telephone poles are replaced annually in the U.S. These end-of-life poles have both chlorine and arsenic-containing preservatives that make their disposal difficult. Thus, they are simply left to rot in storage facilities or other locations.
When disposal of treated wood waste sources is not practical, recycling of the waste is the next best option. When landfilling and/or recycling presents difficulties and/or are not economically feasible incineration remain the primary option for disposal of the waste source. However, incineration is known to result in the generation and atmospheric release of toxic compounds and increases CO2 emissions. This is a result of the chemicals, such as preservatives, that are used to treat the wood sources, such as creosote, chlorinated phenols, arsenic-containing preservatives such as chromium arsenate and chromated copper arsenate, and other toxic chemicals.
There are various forms of treated wood sources that require landfilling, recycling and/or conventional incinerating in the U.S. and worldwide. These include for example, railroad ties, cross ties, RR crossing roadways, telephone poles, utility poles, cross arm members, bridge timbers, decking, walkways, dock timbers and wharf pilings, lake and ocean pier/pilings, landscaping timbers and edging, treated outdoor engineering structural and other reinforced wood composites, and other end-of-life treated wood materials. Still further treated wood waste sources abound in need for efficient processing, recycling and/or disposal and can be processed according to the present invention as one skilled in the art will appreciate.
As a result, there remains a need for efficient processing of a variety of treated wood waste sources. Accordingly, it is an objective of the claimed invention to solve the long-standing problem and need in the art for efficient methods for processing of treated wood waste sources.
A further object of the invention is to provide methods, systems, and/or processes for utilizing thermolysis methods to safely and efficiently convert such waste sources to a Clean Fuel Gas and Biochar without the generation of (and beneficially the removal of) toxic byproducts, including creosote and small molecules, including chlorinated phenols and polymers, commonly used in these waste input streams. Toxic byproducts further include, for example, VOCs, aromatics and polycyclic aromatic hydrocarbons (PAHs), dioxins and furans, including halogenated dibenzodioxins and halogenated dibenzofurans, biphenyls, pyrenes, cadmium, lead, antimony, arsenic, beryllium, chlorofluorocarbons (CFCs), mercury, nickel and other organic compounds. As a result, the methods, systems, and/or processes of the invention meet even the most rigid environmental standards.
A further object of the invention is to provide methods, systems, and/or processes for utilizing thermolysis methods to safely and efficiently convert various waste sources to a Clean Fuel Gas and Biochar. In particular, the generation of a Clean Fuel Gas provides a desirable waste-to-energy pathway from a previously unutilized waste source through the recycling of tars and oils to generate Clean Fuel Gas to thereby reuse the energy that went into the original fabrication. In a further application, the generation of the Biochar (can also be referred to as coke) is suitable for further use as a soil amendment, water treatment, and/or various applications. A further object of the invention is to utilize thermolysis methods to destroy (and beneficially not generate any additional) toxic halogenated organic compounds or hazardous inorganic chemicals present in certain components of the waste sources.
A further object of the invention is to utilize thermolysis methods to generate clean, useable fuel gas sources substantially-free or free of halogenated organic compounds (including VOCs).
Other objects, advantages and features of the present invention will become apparent from the following specification taken in conjunction with the accompanying drawings.